Chapter 5 : Combustion in SI Engines¶

Example 5.1 Page No : 178¶

In [1]:
#Given:
theta_s = 25.      #Angle at which spark occured before top dead centre in degrees
theta_d = 3.      #Angle at which delay ended before top dead centre in degrees
theta_c = -12.      #Angle at which combustion finish after top dead centre in degrees
p = 15.      #Percentage increase of delay period at half clomath.sing the throttle

#Solution:
DP = theta_s-theta_d      #Delay period in degrees
CP = theta_d-theta_c      #Combustion period in degrees
#(a)Full throttle, half speed
DA1 = DP/2      #Delay angle in degrees
TP1 = DA1+CP      #Total period in degrees
TS1 = TP1+theta_c      #Time of spark before top dead centre in degrees
#(b)Half throttle, half speed
DA2 = (DP/2)+(DP/2)*p/100      #Delay angle in degrees
TP2 = DA2+CP      #Total period in degrees
TS2 = TP2+theta_c      #Time of spark before top dead centre in degrees

#Results:
print " a)Full throttle, half speed\t Time of spark before top dead centre is %d degree"%(TS1)
print " a)Half throttle, half speed\t Time of spark before top dead centre is %.2f degree"%(TS2)

 a)Full throttle, half speed	 Time of spark before top dead centre is 14 degree
a)Half throttle, half speed	 Time of spark before top dead centre is 15.65 degree